The Rusty Nail is a cocktail crafted by blending Scotch whisky with Drambuie, typically in a half and half ratio and served over ice in an old-fashioned glass, also known as a rocks glass. However, for a different presentation, it can be served "up" in a stemmed glass.

The cocktail, historical accounts state, originated in 1937 in England, but was called by a different name then. In 1915, the inaugural British Industries Fair (BIF) took place at London's Royal Agricultural Hall, which was aimed at kickstarting domestic production of previously imported goods. Subsequently, venues were assigned for the BIF exhibitions that would last a fortnight. These two weeks transformed the centre into England's premiere attraction. In 1937, amid BIF's creative fervour, a drink nameless but noteworthy came up, eventually dubbed the BIF. 

Post-fair, it languished in obscurity until the 1950s, when it claimed the title of New York's trendiest cocktail. In between in 1942, the cocktail made a cameo, this time linked with the name of artist Theodore Anderson, who is rumoured to be its creator.

During the Vietnam War, US forces stationed in Bangkok brought forth the "Mig-21," christening the BIF with a new identity. In Manhattan, it found its niche as D&S, blending Drambuie and Scotch, the key elements in the Rusty Nail. Across the Midwest, it answered to the moniker "Knucklehead," while in New York, it assumed the guise of "Little Club No. 1." Amidst this nomenclature chaos, the cocktail's definitive name solidified in 1963 when Gina MacKinnon, chairwoman of the Drambuie Liqueur Company, formally endorsed the concoction as Rusty Nail in The New York Times. 

Discrepancies in historical accounts abound, with some citing 1963 as the pivotal year, while others assert it happened in 1967. The ascent of the Rusty Nail to stardom can be attributed to several factors, with Club 21 playing a pivotal role. Despite the misconception that the drink originated at the club, its association with the Rusty Nail has solidified its prominence in cocktail culture. Come the 1970s, it had cemented its status as a favourite libation among the Rat Pack Boys—Frank Sinatra, Dean Martin, Sammy Davis Jr., Joey Bishop, and Peter Lawford.

The Rusty Nail moniker itself boasts several origin theories. One tale suggests that the bartender used a literal rusty nail to stir the concoction. Another posits that the drink's golden hues resembled a rusty nail. Alternatively, it's also said that the name was borrowed from the rusty nails used for securing Drambuie cases. Regardless of the true genesis, the name endured. 

While the core of a Rusty Nail drink is Drambuie, creative bartenders have ventured into experimenting with alternative spirits to replace the traditional whisky with tequila, mescal, or even gin. The inherent richness and nuanced flavour profile provided by Drambuie often render additional mixers or syrups unnecessary in crafting the cocktail.